Soil-resistant pile fabric



Patented Dec. 23, 1952 SOIL-RESISTANT PILE FABRIC Edward J. Cogovan andEdwin D. Frideri'ci, Am-

sterdam, N. Y., assignors to Mohawk Carpet M1115, Inc., Amsterdam, N.Y., a corporation of New York Application March 8, 1951, Serial No.214,526

14 Claims.

1 This invention relates to pile fabrics, such as carpets and rugs, andalso velvets and plushes used as dress, upholstery, and draperymaterials.

More particularly, the invention is concerned with a novel pile fabricof the kinds referred to, in which the pile, although made of yarnscontaining a substantial proportion of vegetable or synthetic fibers orboth, has a reduced tendency to become permanently soiled in use. Theinvention further comprehends a method, by which fabrics havinga pilemade of the yarns mentioned may be easily treated to inhibit theirbecoming permanently soiled and discolored. While the principles of theinvention may be utilized with benefit in the production of all types ofpile fabric containing the specified pile yarns, it offers specialadvantages in connection with floor covering fabrics and its applicationto that field of use will, accordingly, be set forth in detail forpurposes of explanation.

Until quite recently, it has been the common practice in the manufactureof carpeting to make the pile of all-wool yarns, since a pile made ofsuch yarns is of attractive appearance, does not crush readily in use,and has excellent wearing qualities. In addition, a pile made of woolyarns resists permanent soiling and, when the pile collects dirt, thedirt may be readily removed by sweeping, beating, vacuum cleaning,shampooing, etc. As a result, a pile made of such yarns is unlikely tobecome permanently discolored, except after long periods of use underextremely heavy and dirty traffic conditions. Pile yarns made of otheranimal fibers, such as mohair, also resist permanent soiling and,although the reason why animal fiber yarns have this characteristic isnot known, it is a well recognized phenomenon. Accordingly, the yarnsused for the pile in carpeting, upholstery materials for car seats, forexample, and for other uses, in which the material becomes dirty andmust be cleaned from time to time, have regularly been made in the pastof animal fibers.

In the last few years, the great increases in the price of wool and theshort supply of that fiber, particularly of the grade suitable for usein carpets and rugs, have led to the employment of other fibers in thespinning of pile yarns for carpets. Thus, carpets have been producedboth experimentally and for commercial sale, in which the pile yarnshave contained various vegetable and synthetic "fibers, either alone orin blends with or without wool. Example of vegetable and. syntheticmaterials so employed in the spininng of pile yarns for carpet useinclude staple fibers of viscose rayon, acetate rayon, nylon, the fiberknown commercially as saran (polymerized vinyl idene chloride), jute,cotton, e'tc., and mixtures thereof. Other pile yarns have been spunentirely from staple rayon of the two types or cotton. Such pile yarnsspun from blends of wool and vegetable or synthetic fibers or both andalso made wholly of synthetic or vegetable fibers or mixtures thereofhave been found to produce a pile satisfactory in appearance anddurability. However, all pile yarns, which contain a substantialquantity, for example, in excess of 20%, of vegetable fibers orsynthetic fibers, or both, have been found to produce a pile which soilsrapidly in use and cannot be readily cleaned, by

the usual methods, so that it becomes permanently discolored.

The present invention is, accordingly, directed to the provision of anovel pile fabric, in which the pile is made of yarns containing asubstantial proportion of vegetable or synthetic fibers or both andresists permanent soiling much better than the pile of prior fabricsmade of the same pile yarns. The new fabrics have the statedcharacteristic by reason of having been treated in accordance with thenew method.

For a better understanding of the invention, reference may be made tothe accompanying drawing, in which:

Fig. 1 is a view on an enlarged scale and in perspective of one form ofthe new fabric suitable for use'as a floor covering; and

Fig. 2 is a view similar to Fig, 1 of another form of the fabric.

The fabric shown in Fig. l is of conventional velvet carpet constructionand it includes a backing made up of stuffer warps l0, binder warps orfine chains H in two sets, and weft yarns l2, l3 lying, respectively,above and below the stulfer warps and bound in place by the binderwarps. The pile of the fabric is made up of heavy pile yarns 14, each ofwhich has a portion 14a bound beneath a weft yarn l2 and another portionMb projecting upwardly in the form of a pair of tuft legs. In theweaving of the fabric, the pile yarns are raised as loops over pilewires provided with knives and, upon withdrawal of each wire, the loopsof pile yarn thereover are cut. This permits the yarns forming the tuftlegs to untwist and expand somewhat and the cut ends [40 of the yarnsare sheared in finishing operations, so that these ends liesubstantially in a plane and together form the major part of the visiblepart of the surface of the pile.

The fabric shown in Fig. 2 is of conventional tapestry carpet weave andit includes stuffer warps l5, binder warps or fine chains 16 in twosets, and weft yarns ll, l8 lying, respectively, above and below thestuifer warps and bound in place by the binder warps. The pile of thefabric is formed by heavy pile yarns 19, which have portions [9aanchored in the backing by being passed beneath weft yarns ll. Duringthe weaving, each pile yarn is raised over a non-cutting pile wire toform a loop 20 between each two adjacent weft yarns IT and, upon removalof the wires, the tuft yarns remain as loops. The tops and the sides ofthe loops adjacent the tops then form the visible part of the surface ofthe pile.

When the pile yarns employed for forming the.

cut or loop pile shown, respectively, in Figs. 1 and 2, are made whollyof wool or other animal fibers or include with such fibers only arelatively small proportion of vegetable or synthetic fibers or both,the pile has little tendency to become permanently soiled in use and,when dirt collects in and on the pile, the dirt can be removed by' anyof the usual methods. However, if the pile yarns contain a substantialproportion of vegetable or synthetic fibers or both, the pile is subjectto permanent soiling and discoloration, since, when it becomes dirty, itcannot be restored to its original condition by ordinary cleaning. Thus,a pile made of yarns spun from a blend of 50% wool and the remaindermade up of viscose rayon, acetate rayon, nylon, the commercial fiberknown as Saran, or other synthetic fibers soon becomes permanentlydiscolored in use. Similarly, if the pile is made up wholly of syntheticfibers, either alone or in mixture, it does not resist permanentsoiling. The presence of vegetable fibers, such as cotton, jute, ramie,etc. in the pile yarns likewise makes the pile susceptible to permanentsoiling and, in general, it may be said that the presence in pile yarnof vegetable fibers or synthetic fibers, or both, in substantial amountsin excess of 20% causes a pile made therefrom to be subject to permanentsoiling, with this tendency increasing as the proportion of thevegetable and synthetic fibers in the pile yarns is increased. On thecontrary, a pile made of yarns containing only animal fibers, such aswool, mohair, etc., or various blends of such animal fibers, does notdiscolor permanently, except after long periods of use, and can bereadily freed from dirt.

The fabric of the invention comprises a pile made of yarns, whichinclude a substantial proportion of vegetable or synthetic fibers orboth, but the tendency of such a pile to become permanently discoloredin use is greatly reduced in the fabric by applying to the visibleportions of the pile a coating of extremely fine colloidal particles ofsilica, either alone or in combination with a minor proportion ofsimilar particles of other light colored inorganic substances, which aresubstantially insoluble in water and are apparently inert in effect. Itis important that the particles in such a coating have a size such thatcolloidal dispersions may be readily made therefrom. Such particlesnormally range in size from about 0.025 micron toabout 10 microns, andthe coating should have a weight ranging from about 0.15 oz. to about0.5 oz. per square yard of pile surface. Particles of not to exceed 6microns are preferred.

The coating materials giving best results are colloidal solutions ofsilica, and there are a number of such colloidal solutions of silicaavailable commercially. Colloidal solutions of certain clays, such asthat known commercially as Atta Clay SF, give fair results in thepractice of the practice of the invention. Atta Clay SF is a complexhydrated aluminum magnesium silicate containing in its commercial formabout 67% SiOz, and the remainder, which is made up of 12.5% A1203,about 11.5% MgO, and minor amounts of FezOs, CaO, and other compounds,is inert. In this clay, the particles have a size ranging from about0.4-0.6 micron.

In applying the coating, the colloidal solution is diluted, until thesolids present have a dry weight of about 5%, and the solution may beapplied to the pile by spraying, brushing, or other well known methods.After the application of the solution to form a coating having a weightper square yard of pile surface within the range specified, the pile isdried, as by passing the fabric through the usual drying equipment.

The coating is preferably confined to the visible portion of the pileand, in the case of a cut pile-fabric of the type shown in Fig. l, theparticles of the coating material, indicated'at 2|,

cover the cut ends I40 of the tuft legs and some of the particles mayalso adhere to the fibers within the yarn adjacent the ends of thefibers. In the case of a loop pile fabric, as shown in Fig. 2, theparticles 23 of coating material coat the portions of the loops exposedat the surface of the pile and such portions include the tops of thepile loops and parts of the sides of the loops adjacent the tops.

The application of the coating material -to produce a coatinghaving aweight. less than about 0.15 oz. per square yard of pile surface impartsto the pile some tendency to resist soiling, but not enough to begenerally useful. Preferably, the coating material is app-lied toproduce a coating weighing not less than about 0.25 oz. per square yardof pile surface. It is not particularly objectionable to make-thecoating somewhat heavier than 0.5 oz. per square yard of ile surface,but any excess of the coating over a weight of about 0.5 oz. per squareyard of pile surface appears to dust oil in use and thus be lost. Also,if an excessive amount of the light colored coating material is appliedto the pile, it imparts a light cast thereto, which may beobjectionable.

The application of the coating material to a pile made of dyed yarntends to lighten the color and this may be corrected in various ways.One method of overcoming any objectionable color change resulting fromthe application of the coating material involves dyeing the pile yarn aslightly darker shade than that ultimately desired, the coating thenlightening the pile to the desired shade. Another method, which may beemployed in some instances, involves adding a minute amount, such as asmall fractional percentage, of carbon black to the coating material todarken it slightly before its application. Also, coloring material maybe added to the coating material before it is applied to give it a colorclosely approximating that of the pile, on which it is to be used.

The lightening of the color of the pile by the application of a coatingof a weight near the upper end of the range specified is useful inconnection with white pile yarns, since, when the coating is to beapplied, the yarns, in some instances, need not be bleached. Also, thecoating tends to give the yarns a truer white color and, because of thesoil resistance imparted to the yarns by the coating, the whiteness isretained in the use of the carpet.

While resistance to p ranentso ling m b imparted to; a p le made of; ple-yarn con n substantial. proportion of vegetable fibers or synt icfibrs or b th: by app1y s-th i c to; the yarns beforethey are woven intothe fabric, this procedure is expensive, becaus'ethe coating is appliedtoportions of the yarn, which are. not visible in thepile'andthus-do notrequire the coating; Also, if; the yarns are coated before being woven,into the fabric, the passage of the yarns through the heddles and reedofthe loom is likely to removea substantial proportion of the coating.

It is preferable to apply the coati to the completed fabrics at; themillbefore they are shipped out, but the coating-can be applied to afabric already installed. Before. the application of the coating. to afabric, which has been in use, the dirt should be removed: tothe extentpossible before the coating is applied; and the coating may then, beconveniently applied by spraying. If the fabric already installed is tobe cleaned by shampooing with, any ofthe usual foaming detergentcompositions commonly employed for the purpose, the coatingmaterial maybe added to the, shampooing compound. After the shampooing has beencompleted, the foam may be, removed. by a vacuum cleaner and the coatingthen remains on the fibers. The application of the coating during theshampooing may be employed either to produce aninitial coating or torestore the original coating on a pile, which requires cleaning byshampooing. The particles of the coating material in a coating having aweight per square yard within the ranges specified appear to adhere tothe fibers for indefiniteperiods, although, it may be desirable to renewthe coating. from time to time in the manner described.

The application of the coating to a pile made of yarns spun from a blendof wool and vegetable fibers or synthetic fibers or both; does notimpair and, on the contrary, appears to enhance the resistance of thewool to permanent soiling.

We claim:

1.. A fabric having a pile resistant to permanent soiling, whichcomprises a. backing and pile yarns having portions anchored; in thebacking and other portions projecting; above the backing toprovide thepile, the pile yarns including a substantial proportion in excess of 20%of, fibers of'the class consisting of vegetable. and synthetic fibers,and a coating of colloidal particles of inorganic, water insolublesubstances containing a major proportion! of silica on the router orexposed portions only of the pile yarns forming the visible part of thepile, the coating having a weight ranging from about 0.15 oz. to about0.5 oz. per square yard of pile surface.

2. A fabric having a pile resistant to permanent soiling, whichcomprises a backing and pile yarns having portions anchored in thebacking and other portions projecting above the backing as tufts formingthe pile, the ends of the tufts lying in the upper surface of the pile,the pile yarns including a substantial proportion in excess of 20% offibers of the class consisting of vegetable and synthetic fibers, and acoating of colloidal particles of inorganic, water insoluble substancescontaining a major proportion of silica on the outer or exposed portionsonly of the yarns forming the visible part of the pile and including theends of the tufts, the coating having a weight ranging from about 0.15oz. to about 0.5 oz, per square yard of pile surface.

3, A, fabric having a pile resistant: topfirmasnent soiling,- whichcomprisesa backingand pile yarns having portions anchored in the,backing and other portions projecting above the backing to-provide thepile, the pile yarns containing a blend of fibers including wool and asubstantial proportion in excess of 20% of at least. one fiber from theclass consisting of vegetable and synthetic fibers, and a coating ofcolloidal particles of inorganic, water insoluble substances containinga major proportion of silica on theouter or exposed portionsponly of thepile yarns forming the visible part of the pile, the coating having aweight ranging from about 0.15 oz. to about 0. oz. per square yard ofpile surface.

4;. A fabric having a pile resistant to permanent soiling, whichcomprises a backing and pile yarns having portions anchored in thebacking and other portions projecting above the backs ing toprovide thepile, the pile yarns including a, substantial proportion in excess of20% of fibers of the class consisting ofvegetable and synthetic fibers,and a coating of colloidal parti:-. cles of inorganic, water insolublesubstances (30 11? taining a major proportion of silica on the outer orexposed portions only of the pile yarnsforming. the visible part of thepile, the coating con.- taining a minute quantity of carbon black par-.-ticles, distributed therein, thecoating having a weight ranging fromabout 0.15 oz. to about 0.5 oz. per square yard of pile surface.

5. A fabric having a pile resistant to perma: nent soiling, whichcomprises a backing and dyed pile yarns having portions anchored in thebacking and other portions projecting above the backing to provide thepile, the pile yarns including-a substantial proportion in excess of 20%of fibers of'theclass consisting of vegetable and synthetic fibers, anda coating of colloidal particles of in.- organic, water insolublesubstances containing a major proportion of silica on the outer or ex.posed portions only of the pile yarns forming the visible part of thepile, the coating containing coloring matter giving it substantially thesame color as the pile yarns and the coating having a weight rangingfrom about 0.15 oz. to about 0.5 oz. per square yard of pile surface.

6. A method of imparting resistance to permanent soiling to the pile ofa fabric, in which the pile is made of pile yarns including asubstantial proportion in excess of 29% of fibers of the classconsisting of vegetable and synthetic fibers, which comprises applyingtothe outer or exposed portions of the pile only a dilute colloidalwater solution of inorganic substances containing a major proportion ofsilica, to form a coating of the particles of a weight in solids rangingfrom about 0.15 oz. to about 0.5 oz. per square yard of pile surface,and drying the treated pile.

'7. A method of imparting resistance to permanent soiling to the pile ofa fabric, in which the pile is made of pile yarns including asubstantial proportion in excess of 20% of fibers of the classconsisting of vegetable and synthetic fibers, which comprises sprayingthe outer or exposed surface only of the pile with a dilute colloidalwater solution of inorganic substances containing a major proportion ofsilica, to form a coating of the particles of a weight in solids rangingfrom about 0.15 oz. to about 0.5 oz. per square yard of pile surface,and drying the treated pile.

8. A method of imparting resistance to permanent soiling to the pile ofa fabric, in which the pile is made of pile yarns including asubstantial proportion in excess of 20% of fibers of the classconsisting of vegetable and synthetic fibers, which comprises applyingto the outer or exposed portions of the pile only a dilute colloidalwater so lution of inorganic substances containing a major proportion ofsilica, the colloidal solution containing about 5% of the dry weight ofthe solids, to form a coating of the particles of a weight in solidsranging from about 0.15 oz. to about 0.5 oz. per square yard of pilesurface, and drying the pile.

9. A method of imparting resistance to permanent soiling to the pile ofa fabric, in which the pile is made of pile yarns including, asubstantial proportion in excess of 20% of fibers of the classconsisting of vegetable and synthetic fibers, which comprises shampooingthe pile with a foaming shampoo solution, to which has been added adilute colloidal water solution of particles of inorganic substancescontaining a major proportion of silica, the particles forming a coatingon the pile of a weight in solids ranging from about 0.15 oz. to about0.5 oz. per square yard of pile surface, removing the foam from thepile, and drying the pile.

10. A fabric having a pile resistant to permanent soiling, whichcomprises a backing and pile yarns having portions anchored in thebacking and other portions projecting above the backing to provide thepile, the pile yarns including a substantial proportion in excess of 20%of fibers of the class consisting of vegetable and synthetic fibers, anda coating of colloidal particles of silica on the portions of the pileyarns forming the visible part only of the pile, the coating having aweight ranging from about 0.15 oz. to about 0.5

oz. per square yard of pile surface.

11. A fabric having a cut pile resistant to permanent soiling, whichcomprises backing and pile yarns having portions anchored in the backingand other portions projecting above the backing as tufts forming thepile, the ends of the tufts lying in the top surface of the pile and thepile yarns including a substantial proportion in excess of 20% of fibersof the class consisting of vegetable and synthetic fibers, and a coatingof colloidal particles of silica on the top surface portion only of thepile, the coating having a Weight of about 0.15 oz. to about 0.5 oz. persquare yard of pile surface.

12. A method of imparting resistance to permanent soiling to the pile ofa fabric, in which the pile is made of pile yarns including asubstantial proportion in excess of 20% of fibers of the classconsisting of vegetable and synthetic fibers which comprises applying tothe outer or exposed portion of the pile only a colloidal water solutionof silica particles, to form a coating of the particles of a weight insolids ranging from about 0.15 oz. to about 0.5 oz. per square yard ofpile surface, and drying the treated pile.

13. A pile fabric for floor covering purposes which comprises a backingincluding stuffer and binder warp yarns, weft yarns held against thestulfer warp yarns of the binder warp yarns, and pile yarns havingportions anchored beneath Weft yarns and other portions extendingupwardly out of the backing to form the elements of a pile, the pileyarns including a substantial proportion in excess of 20% of fibers ofthe class consisting of vegetable and synthetic fibers, and a coating ofcolloidal particles of silica on the outer or exposed portions only ofthe pile elements, the coating having a weight of about 0.15 oz. toabout 0.5 oz. per square yard of pile surface.

14. A pile fabric for floor covering purposes which comprises a backingincluding stufier and binder warp yarns, weft yarns held against thestuffer warp yarns by the binder warp yarns, and and pile yarns havingportions anchored beneath weft yarns and other portions extendingupwardly out of the backing to form pile tufts, the pile yarns includinga substantial proportion in excess of 20% of fibers of the classconsisting of vegetable and synthetic fibers, and a coating of colloidalparticles of silica, on the outer or exposed ends only of the tufts, thecoating having a weight of about 0.15 to about 0.5 oz. per square yardof pile surface.

EDWARD J. GOGOVAN. EDWIN D. FRIDERICI.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,608,418 Payne Nov. 23, 19261,629,241 Ubbelohde May 17, 1927 1,943,519 Denning Jan. 16, 19342,362,299 Nutter Nov. 7, 1944 2,443,512 Powers et al June 15, 19482,526,684 Powers et a1 Oct. 24, 1950 2,527,329 Powers et a1 Oct. 24,1950 2,570,750 Bauer Oct. 9, 1951

